Organic electroluminescent materials and devices

ABSTRACT

A compound useful as a host material in phosphorescent light emitting devices is disclosed. The compound has the following formula: 
     
       
         
         
             
             
         
       
     
     in which R represents an adjacent di-substitution having the following formula fused to ring A:

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(e) to U.S.Provisional Application Ser. No. 62/548,559, filed Aug. 22, 2017, theentire contents of which is incorporated herein by reference.

FIELD

The present invention relates to compounds for use as hosts and devices,such as organic light emitting diodes, including the same.

BACKGROUND

Opto-electronic devices that make use of organic materials are becomingincreasingly desirable for a number of reasons. Many of the materialsused to make such devices are relatively inexpensive, so organicopto-electronic devices have the potential for cost advantages overinorganic devices. In addition, the inherent properties of organicmaterials, such as their flexibility, may make them well suited forparticular applications such as fabrication on a flexible substrate.Examples of organic opto-electronic devices include organic lightemitting diodes/devices (OLEDs), organic phototransistors, organicphotovoltaic cells, and organic photodetectors. For OLEDs, the organicmaterials may have performance advantages over conventional materials.For example, the wavelength at which an organic emissive layer emitslight may generally be readily tuned with appropriate dopants.

OLEDs make use of thin organic films that emit light when voltage isapplied across the device. OLEDs are becoming an increasinglyinteresting technology for use in applications such as flat paneldisplays, illumination, and backlighting. Several OLED materials andconfigurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and5,707,745, which are incorporated herein by reference in their entirety.

One application for phosphorescent emissive molecules is a full colordisplay. Industry standards for such a display call for pixels adaptedto emit particular colors, referred to as “saturated” colors. Inparticular, these standards call for saturated red, green, and bluepixels. Alternatively the OLED can be designed to emit white light. Inconventional liquid crystal displays emission from a white backlight isfiltered using absorption filters to produce red, green and blueemission. The same technique can also be used with OLEDs.The white OLEDcan be either a single EML device or a stack structure. Color may bemeasured using CIE coordinates, which are well known to the art.

One example of a green emissive molecule is tris(2-phenylpyridine)iridium, denoted Ir(ppy)₃, which has the following structure:

In this, and later figures herein, we depict the dative bond fromnitrogen to metal (here, Ir) as a straight line.

As used herein, the term “organic” includes polymeric materials as wellas small molecule organic materials that may be used to fabricateorganic opto-electronic devices. “Small molecule” refers to any organicmaterial that is not a polymer, and “small molecules” may actually bequite large Small molecules may include repeat units in somecircumstances. For example, using a long chain alkyl group as asubstituent does not remove a molecule from the “small molecule” class.Small molecules may also be incorporated into polymers, for example as apendent group on a polymer backbone or as a part of the backbone. Smallmolecules may also serve as the core moiety of a dendrimer, whichconsists of a series of chemical shells built on the core moiety. Thecore moiety of a dendrimer may be a fluorescent or phosphorescent smallmolecule emitter. A dendrimer may be a “small molecule,” and it isbelieved that all dendrimers currently used in the field of OLEDs aresmall molecules.

As used herein, “top” means furthest away from the substrate, while“bottom” means closest to the substrate. Where a first layer isdescribed as “disposed over” a second layer, the first layer is disposedfurther away from substrate. There may be other layers between the firstand second layer, unless it is specified that the first layer is “incontact with” the second layer. For example, a cathode may be describedas “disposed over” an anode, even though there are various organiclayers in between.

As used herein, “solution processable” means capable of being dissolved,dispersed, or transported in and/or deposited from a liquid medium,either in solution or suspension form.

A ligand may be referred to as “photoactive” when it is believed thatthe ligand directly contributes to the photoactive properties of anemissive material. A ligand may be referred to as “ancillary” when it isbelieved that the ligand does not contribute to the photoactiveproperties of an emissive material, although an ancillary ligand mayalter the properties of a photoactive ligand.

As used herein, and as would be generally understood by one skilled inthe art, a first “Highest Occupied Molecular Orbital” (HOMO) or “LowestUnoccupied Molecular Orbital” (LUMO) energy level is “greater than” or“higher than” a second HOMO or LUMO energy level if the first energylevel is closer to the vacuum energy level. Since ionization potentials(IP) are measured as a negative energy relative to a vacuum level, ahigher HOMO energy level corresponds to an IP having a smaller absolutevalue (an IP that is less negative) Similarly, a higher LUMO energylevel corresponds to an electron affinity (EA) having a smaller absolutevalue (an EA that is less negative). On a conventional energy leveldiagram, with the vacuum level at the top, the LUMO energy level of amaterial is higher than the HOMO energy level of the same material. A“higher” HOMO or LUMO energy level appears closer to the top of such adiagram than a “lower” HOMO or LUMO energy level.

As used herein, and as would be generally understood by one skilled inthe art, a first work function is “greater than” or “higher than” asecond work function if the first work function has a higher absolutevalue. Because work functions are generally measured as negative numbersrelative to vacuum level, this means that a “higher” work function ismore negative. On a conventional energy level diagram, with the vacuumlevel at the top, a “higher” work function is illustrated as furtheraway from the vacuum level in the downward direction. Thus, thedefinitions of HOMO and LUMO energy levels follow a different conventionthan work functions.

More details on OLEDs, and the definitions described above, can be foundin U.S. Pat. No. 7,279,704, which is incorporated herein by reference inits entirety.

SUMMARY

Organic materials containing indolocarbazoles and azacarbazole useful ashost materials in PHOLEDs are disclosed. These material can enhance thedevice performance by improving the device lifetime, external quantumefficiency (EQE), and lowering the operational voltage.

A compound having the following Formula I is disclosed:

In Formula I, R represents an adjacent di-substitution having thefollowing formula fused to ring A:

where the bonds with wave lines represent the bonds connected to twoadjacent carbon atoms from the ring A. R^(A), and R^(C) eachindependently represents mono, di, tri, or tetra substitution, or nosubstitution. R^(B) represents mono, or di substitution, or nosubstitution. L¹ and L² each independently represents a direct bond oran organic linker. G¹ and G² are each independently selected from thegroup consisting of aryl, heteroaryl, substituted variants thereof, andcombination thereof; where at least one of G¹ and G² comprises astructure having the formula:

where X¹-X⁸ are each independently selected from the group consisting ofC and N; where at least one of X¹-X⁸ is N; where the maximum number of Natoms in a ring can connect to each other is two; where R^(A), R^(B),R^(C), R^(D), and R^(E) are each independently selected from the groupconsisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl,heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl,alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl,carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl,sulfonyl, phosphino, and combinations thereof; and where any twosubstituents may be joined or fused together to form a ring.

An organic light emitting diode/device (OLED) including an anode, acathode, and an organic layer, disposed between the anode and thecathode, where the organic layer comprises the compound of Formula I isdisclosed.

A consumer product comprising the OLED is also disclosed. A formulationcontaining the compound of Formula I is also disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an organic light emitting device.

FIG. 2 shows an inverted organic light emitting device that does nothave a separate electron transport layer.

DETAILED DESCRIPTION

Generally, an OLED comprises at least one organic layer disposed betweenand electrically connected to an anode and a cathode. When a current isapplied, the anode injects holes and the cathode injects electrons intothe organic layer(s). The injected holes and electrons each migratetoward the oppositely charged electrode. When an electron and holelocalize on the same molecule, an “exciton,” which is a localizedelectron-hole pair having an excited energy state, is formed. Light isemitted when the exciton relaxes via a photoemissive mechanism. In somecases, the exciton may be localized on an excimer or an exciplex.Non-radiative mechanisms, such as thermal relaxation, may also occur,but are generally considered undesirable.

The initial OLEDs used emissive molecules that emitted light from theirsinglet states (“fluorescence”) as disclosed, for example, in U.S. Pat.No. 4,769,292, which is incorporated by reference in its entirety.Fluorescent emission generally occurs in a time frame of less than 10nanoseconds.

More recently, OLEDs having emissive materials that emit light fromtriplet states (“phosphorescence”) have been demonstrated. Baldo et al.,“Highly Efficient Phosphorescent Emission from OrganicElectroluminescent Devices,” Nature, vol. 395, 151-154, 1998;(“Baldo-I”) and Baldo et al., “Very high-efficiency green organiclight-emitting devices based on electrophosphorescence,” Appl. Phys.Lett., vol. 75, No. 3, 4-6 (1999) (“Baldo-II”), are incorporated byreference in their entireties. Phosphorescence is described in moredetail in U.S. Pat. No. 7,279,704 at cols. 5-6, which are incorporatedby reference.

FIG. 1 shows an organic light emitting device 100. The figures are notnecessarily drawn to scale. Device 100 may include a substrate 110, ananode 115, a hole injection layer 120, a hole transport layer 125, anelectron blocking layer 130, an emissive layer 135, a hole blockinglayer 140, an electron transport layer 145, an electron injection layer150, a protective layer 155, a cathode 160, and a barrier layer 170.Cathode 160 is a compound cathode having a first conductive layer 162and a second conductive layer 164. Device 100 may be fabricated bydepositing the layers described, in order. The properties and functionsof these various layers, as well as example materials, are described inmore detail in U.S. Pat. No. 7,279,704 at cols. 6-10, which areincorporated by reference.

More examples for each of these layers are available. For example, aflexible and transparent substrate-anode combination is disclosed inU.S. Pat. No. 5,844,363, which is incorporated by reference in itsentirety. An example of a p-doped hole transport layer is m-MTDATA dopedwith F₄-TCNQ at a molar ratio of 50:1, as disclosed in U.S. PatentApplication Publication No. 2003/0230980, which is incorporated byreference in its entirety. Examples of emissive and host materials aredisclosed in U.S. Pat. No. 6,303,238 to Thompson et al., which isincorporated by reference in its entirety. An example of an n-dopedelectron transport layer is BPhen doped with Li at a molar ratio of 1:1,as disclosed in U.S. Patent Application Publication No. 2003/0230980,which is incorporated by reference in its entirety. U.S. Pat. Nos.5,703,436 and 5,707,745, which are incorporated by reference in theirentireties, disclose examples of cathodes including compound cathodeshaving a thin layer of metal such as Mg:Ag with an overlyingtransparent, electrically-conductive, sputter-deposited ITO layer. Thetheory and use of blocking layers is described in more detail in U.S.Pat. No. 6,097,147 and U.S. Patent Application Publication No.2003/0230980, which are incorporated by reference in their entireties.Examples of injection layers are provided in U.S. Patent ApplicationPublication No. 2004/0174116, which is incorporated by reference in itsentirety. A description of protective layers may be found in U.S. PatentApplication Publication No. 2004/0174116, which is incorporated byreference in its entirety.

FIG. 2 shows an inverted OLED 200. The device includes a substrate 210,a cathode 215, an emissive layer 220, a hole transport layer 225, and ananode 230. Device 200 may be fabricated by depositing the layersdescribed, in order. Because the most common OLED configuration has acathode disposed over the anode, and device 200 has cathode 215 disposedunder anode 230, device 200 may be referred to as an “inverted” OLED.Materials similar to those described with respect to device 100 may beused in the corresponding layers of device 200. FIG. 2 provides oneexample of how some layers may be omitted from the structure of device100.

The simple layered structure illustrated in FIGS. 1 and 2 is provided byway of non-limiting example, and it is understood that embodiments ofthe invention may be used in connection with a wide variety of otherstructures. The specific materials and structures described areexemplary in nature, and other materials and structures may be used.Functional OLEDs may be achieved by combining the various layersdescribed in different ways, or layers may be omitted entirely, based ondesign, performance, and cost factors. Other layers not specificallydescribed may also be included. Materials other than those specificallydescribed may be used. Although many of the examples provided hereindescribe various layers as comprising a single material, it isunderstood that combinations of materials, such as a mixture of host anddopant, or more generally a mixture, may be used. Also, the layers mayhave various sublayers. The names given to the various layers herein arenot intended to be strictly limiting. For example, in device 200, holetransport layer 225 transports holes and injects holes into emissivelayer 220, and may be described as a hole transport layer or a holeinjection layer. In one embodiment, an OLED may be described as havingan “organic layer” disposed between a cathode and an anode. This organiclayer may comprise a single layer, or may further comprise multiplelayers of different organic materials as described, for example, withrespect to FIGS. 1 and 2.

Structures and materials not specifically described may also be used,such as OLEDs comprised of polymeric materials (PLEDs) such as disclosedin U.S. Pat. No. 5,247,190 to Friend et al., which is incorporated byreference in its entirety. By way of further example, OLEDs having asingle organic layer may be used. OLEDs may be stacked, for example asdescribed in U.S. Pat. No. 5,707,745 to Forrest et al, which isincorporated by reference in its entirety. The OLED structure maydeviate from the simple layered structure illustrated in FIGS. 1 and 2.For example, the substrate may include an angled reflective surface toimprove out-coupling, such as a mesa structure as described in U.S. Pat.No. 6,091,195 to Forrest et al., and/or a pit structure as described inU.S. Pat. No. 5,834,893 to Bulovic et al., which are incorporated byreference in their entireties.

Unless otherwise specified, any of the layers of the various embodimentsmay be deposited by any suitable method. For the organic layers,preferred methods include thermal evaporation, ink-jet, such asdescribed in U.S. Pat. Nos. 6,013,982 and 6,087,196, which areincorporated by reference in their entireties, organic vapor phasedeposition (OVPD), such as described in U.S. Pat. No. 6,337,102 toForrest et al., which is incorporated by reference in its entirety, anddeposition by organic vapor jet printing (OVJP), such as described inU.S. Pat. No. 7,431,968, which is incorporated by reference in itsentirety. Other suitable deposition methods include spin coating andother solution based processes. Solution based processes are preferablycarried out in nitrogen or an inert atmosphere. For the other layers,preferred methods include thermal evaporation. Preferred patterningmethods include deposition through a mask, cold welding such asdescribed in U.S. Pat. Nos. 6,294,398 and 6,468,819, which areincorporated by reference in their entireties, and patterning associatedwith some of the deposition methods such as ink jet and organic vaporjet printing (OVJP). Other methods may also be used. The materials to bedeposited may be modified to make them compatible with a particulardeposition method. For example, substituents such as alkyl and arylgroups, branched or unbranched, and preferably containing at least 3carbons, may be used in small molecules to enhance their ability toundergo solution processing. Substituents having 20 carbons or more maybe used, and 3-20 carbons is a preferred range. Materials withasymmetric structures may have better solution processability than thosehaving symmetric structures, because asymmetric materials may have alower tendency to recrystallize. Dendrimer substituents may be used toenhance the ability of small molecules to undergo solution processing.

Devices fabricated in accordance with embodiments of the presentinvention may further optionally comprise a barrier layer. One purposeof the barrier layer is to protect the electrodes and organic layersfrom damaging exposure to harmful species in the environment includingmoisture, vapor and/or gases, etc. The barrier layer may be depositedover, under or next to a substrate, an electrode, or over any otherparts of a device including an edge. The barrier layer may comprise asingle layer, or multiple layers. The barrier layer may be formed byvarious known chemical vapor deposition techniques and may includecompositions having a single phase as well as compositions havingmultiple phases. Any suitable material or combination of materials maybe used for the barrier layer. The barrier layer may incorporate aninorganic or an organic compound or both. The preferred barrier layercomprises a mixture of a polymeric material and a non-polymeric materialas described in U.S. Pat. No. 7,968,146, PCT Pat. Application Nos.PCT/US2007/023098 and PCT/US2009/042829, which are herein incorporatedby reference in their entireties. To be considered a “mixture”, theaforesaid polymeric and non-polymeric materials comprising the barrierlayer should be deposited under the same reaction conditions and/or atthe same time. The weight ratio of polymeric to non-polymeric materialmay be in the range of 95:5 to 5:95. The polymeric material and thenon-polymeric material may be created from the same precursor material.In one example, the mixture of a polymeric material and a non-polymericmaterial consists essentially of polymeric silicon and inorganicsilicon.

Devices fabricated in accordance with embodiments of the invention canbe incorporated into a wide variety of electronic component modules (orunits) that can be incorporated into a variety of electronic products orintermediate components. Examples of such electronic products orintermediate components include display screens, lighting devices suchas discrete light source devices or lighting panels, etc. that can beutilized by the end-user product manufacturers. Such electroniccomponent modules can optionally include the driving electronics and/orpower source(s). Devices fabricated in accordance with embodiments ofthe invention can be incorporated into a wide variety of consumerproducts that have one or more of the electronic component modules (orunits) incorporated therein. A consumer product comprising an OLED thatincludes the compound of the present disclosure in the organic layer inthe OLED is disclosed. Such consumer products would include any kind ofproducts that include one or more light source(s) and/or one or more ofsome type of visual displays. Some examples of such consumer productsinclude flat panel displays, curved displays, computer monitors, medicalmonitors, televisions, billboards, lights for interior or exteriorillumination and/or signaling, heads-up displays, fully or partiallytransparent displays, flexible displays, rollable displays, foldabledisplays, stretchable displays, laser printers, telephones, mobilephones, tablets, phablets, personal digital assistants (PDAs), wearabledevices, laptop computers, digital cameras, camcorders, viewfinders,micro-displays (displays that are less than 2 inches diagonal), 3-Ddisplays, virtual reality or augmented reality displays, vehicles, videowalls comprising multiple displays tiled together, theater or stadiumscreen, and a sign. Various control mechanisms may be used to controldevices fabricated in accordance with the present invention, includingpassive matrix and active matrix. Many of the devices are intended foruse in a temperature range comfortable to humans, such as 18 degrees C.to 30 degrees C., and more preferably at room temperature (20-25 degreesC.), but could be used outside this temperature range, for example, from−40 degree C. to +80 degree C.

The materials and structures described herein may have applications indevices other than OLEDs. For example, other optoelectronic devices suchas organic solar cells and organic photodetectors may employ thematerials and structures. More generally, organic devices, such asorganic transistors, may employ the materials and structures.

The terms “halo,” “halogen,” or “halide” as used interchangeably andrefer to fluorine, chlorine, bromine, and iodine.

The term “acyl” refers to a substituted carbonyl radical (C(O)—R_(s)).

The term “ester” refers to a substituted oxycarbonyl (—O—C(O)—R_(s) or—C(O)—O—R_(s)) radical.

The term “ether” refers to an —OR_(s) radical.

The terms “sulfanyl” or “thio-ether” are used interchangeably and referto a —SR_(s) radical.

The term “sulfinyl” refers to a —S(O)—R_(s) radical.

The term “sulfonyl” refers to a —SO₂—R_(s) radical.

The term “phosphino” refers to a —P(R_(s))₃ radical, wherein each R_(s)can be same or different.

The term “silyl” refers to a —Si(R_(s))₃ radical, wherein each R can besame or different.

In each of the above, R_(s) can be hydrogen or a substituent selectedfrom the group consisting of deuterium, halogen, alkyl, cycloalkyl,heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl,alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, andcombination thereof. Preferred R_(s) is selected from the groupconsisting of alkyl, cycloalkyl, aryl, heteroaryl, and combinationthereof.

The term “alkyl” refers to and includes both straight and branched chainalkyl radicals. Preferred alkyl groups are those containing from one tofifteen carbon atoms and includes methyl, ethyl, propyl, 1-methylethyl,butyl, 1-methylpropyl, 2-methylpropyl, pentyl, 1-methylbutyl,2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl,2,2-dimethylpropyl,and the like. Additionally, the alkyl group may beoptionally substituted.

The term “cycloalkyl” refers to and includes monocyclic, polycyclic, andspiro alkyl radicals. Preferred cycloalkyl groups are those containing 3to 12 ring carbon atoms and includes cyclopropyl, cyclopentyl,cyclohexyl, bicyclo[3.1.1]heptyl, spiro[4.5]decyl, spiro[5.5]undecyl,adamantyl, and the like. Additionally, the cycloalkyl group may beoptionally substituted.

The terms “heteroalkyl” or “heterocycloalkyl” refer to an alkyl or acycloalkyl radical, respectively, having at least one carbon atomreplaced by a heteroatom. Optionally the at least one heteroatom isselected from O, S, N, P, B, Si and Se, preferably, O, S or N.Additionally, the heteroalkyl or heterocycloalkyl group is optionallysubstituted.

The term “alkenyl” refers to and includes both straight and branchedchain alkene radicals. Alkenyl groups are essentially alkyl groups thatinclude at least one carbon-carbon double bond in the alkyl chain.Cycloalkenyl groups are essentially cycloalkyl groups that include atleast one carbon-carbon double bond in the cycloalkyl ring. The term“heteroalkenyl” as used herein refers to an alkenyl radical having atleast one carbon atom replaced by a heteroatom. Optionally the at leastone heteroatom is selected from O, S, N, P, B, Si and Se, preferably, O,S or N. Preferred alkenyl, cycloalkenyl, or heteroalkenyl groups arethose containing two to fifteen carbon atoms. Additionally, the alkenyl,cycloalkenyl, or heteroalkenyl group is optionally substituted.

The term “alkynyl” refers to and includes both straight and branchedchain alkyne radicals. Preferred alkynyl groups are those containing twoto fifteen carbon atoms. Additionally, the alkynyl group is optionallysubstituted.

The terms “aralkyl” or “arylalkyl” are used interchangeably and refer toan alkyl group that is substituted with an aryl group. Additionally, thearalkyl group is optionally substituted.

The term “heterocyclic group” refers to and includes aromatic andnon-aromatic cyclic radicals containing at least one heteroatom.Optionally the at least one heteroatom is selected from O, S, N, P, B,Si and Se, preferably, O, S or N. Hetero-aromatic cyclic radicals may beused interchangeably with heteroaryl. Preferred hetero-non-aromaticcyclic groups are those containing 3 to 7 ring atoms which includes atleast one hetero atom, and includes cyclic amines such as morpholino,piperidino, pyrrolidino, and the like, and cyclic ethers/thio-ethers,such as tetrahydrofuran, tetrahydropyran, tetrahydrothiophene, and thelike. Additionally, the heterocyclic group may be optionallysubstituted.

The term “aryl” refers to and includes both single-ring aromatichydrocarbyl groups and polycyclic aromatic ring systems. The polycyclicrings may have two or more rings in which two carbons are common to twoadjoining rings (the rings are “fused”) wherein at least one of therings is an aromatic hydrocarbyl group, e.g., the other rings can becycloalkyls, cycloalkenyls, aryl, heterocycles, and/or heteroaryls.Preferred aryl groups are those containing six to thirty carbon atoms,preferably six to twenty carbon atoms, more preferably six to twelvecarbon atoms. Especially preferred is an aryl group having six carbons,ten carbons or twelve carbons. Suitable aryl groups include phenyl,biphenyl, triphenyl, triphenylene, tetraphenylene, naphthalene,anthracene, phenalene, phenanthrene, fluorene, pyrene, chrysene,perylene, and azulene, preferably phenyl, biphenyl, triphenyl,triphenylene, fluorene, and naphthalene. Additionally, the aryl groupmay be optionally substituted.

The term “heteroaryl” refers to and includes both single-ringhetero-aromatic groups and polycyclic aromatic ring systems that includeat least one heteroatom. The heteroatoms include, but are not limited toO, S, N, P, B, Si and Se. In many instances, O, S or N are the preferredheteroatoms. Hetero-single ring aromatic systems are preferably singlerings with 5 or 6 ring atoms, and the ring can have from one to sixheteroatoms. The hetero-polycyclic ring systems can have two or morerings in which two atoms are common to two adjoining rings (the ringsare “fused”) wherein at least one of the rings is a heteroaryl, e.g.,the other rings can be cycloalkyls, cycloalkenyls, aryl, heterocycles,and/or heteroaryls. The hetero-polycyclic aromatic ring systems can havefrom one to six heteroatoms per ring of the polycyclic aromatic ringsystem. Preferred heteroaryl groups are those containing three to thirtycarbon atoms, preferably three to twenty carbon atoms, more preferablythree to twelve carbon atoms. Suitable heteroaryl groups includedibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene,benzofuran, benzothiophene, benzoselenophene, carbazole,indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole,triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole,thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine,oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole,indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline,isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine,phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine,phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine,thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine,preferably dibenzothiophene, dibenzofuran, dibenzoselenophene,carbazole, indolocarbazole, imidazole, pyridine, triazine,benzimidazole, 1,2-azaborine, 1,3-azaborine, 1,4-azaborine, borazine,and aza-analogs thereof. Additionally, the heteroaryl group may beoptionally substituted.

Of the aryl and heteroaryl groups listed above, the groups oftriphenylene, naphthalene, anthracene, dibenzothiophene, dibenzofuran,dibenzoselenophene, carbazole, indolocarbazole, imidazole, pyridine,pyrazine, pyrimidine, triazine, and benzimidazole, and the respectiveaza-analogs of each thereof are of particular interest.

The terms alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, alkenyl,cycloalkenyl, heteroalkenyl, alkynyl, aralkyl, heterocyclic group, aryl,and heteroaryl, as used herein, are independently unsubstituted orsubstituted with one or more general substituents.

In many instances, the general substituents are selected from the groupconsisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl,heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, cyclic amino,silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl,acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile,sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

In some instances, the preferred general substituents are selected fromthe group consisting of deuterium, fluorine, alkyl, cycloalkyl,heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl,heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, sulfanyl, andcombinations thereof.

In some instances, the preferred general substituents are selected fromthe group consisting of deuterium, fluorine, alkyl, cycloalkyl, alkoxy,aryloxy, amino, silyl, aryl, heteroaryl, sulfanyl, and combinationsthereof.

In yet other instances, the more preferred general substituents areselected from the group consisting of deuterium, fluorine, alkyl,cycloalkyl, aryl, heteroaryl, and combinations thereof.

The term “substituted” refers to a substituent other than H that isbonded to the relevant position, e.g., a carbon. For example, where R¹represents mono-substituted, then one R¹ must be other than H.Similarly, where R¹ represents di-substituted, then two of R¹ must beother than H. Similarly, where R¹ is unsubstituted, R¹ is hydrogen forall available positions. The maximum number of substitutions possible ina structure (for example, a particular ring or fused ring system) willdepend on the number of atoms with available valencies.

As used herein, “combinations thereof” indicates that one or moremembers of the applicable list are combined to form a known orchemically stable arrangement that one of ordinary skill in the art canenvision from the applicable list. For example, an alkyl and deuteriumcan be combined to form a partial or fully deuterated alkyl group; ahalogen and alkyl can be combined to form a halogenated alkylsubstituent; and a halogen, alkyl, and aryl can be combined to form ahalogenated arylalkyl. In one instance, the term substitution includes acombination of two to four of the listed groups. In another instance,the term substitution includes a combination of two to three groups. Inyet another instance, the term substitution includes a combination oftwo groups. Preferred combinations of substituent groups are those thatcontain up to fifty atoms that are not hydrogen or deuterium, or thosewhich include up to forty atoms that are not hydrogen or deuterium, orthose that include up to thirty atoms that are not hydrogen ordeuterium. In many instances, a preferred combination of substituentgroups will include up to twenty atoms that are not hydrogen ordeuterium.

The “aza” designation in the fragments described herein, i.e.aza-dibenzofuran, aza-dibenzothiophene, etc. means that one or more ofthe C—H groups in the respective fragment can be replaced by a nitrogenatom, for example, and without any limitation, azatriphenyleneencompasses both dibenzo[f,h]quinoxaline and dibenzo[f,h[quinoline. Oneof ordinary skill in the art can readily envision other nitrogen analogsof the aza-derivatives described above, and all such analogs areintended to be encompassed by the terms as set forth herein.

As used herein, “deuterium” refers to an isotope of hydrogen. Deuteratedcompounds can be readily prepared using methods known in the art. Forexample, U.S. Pat. No. 8,557,400, Patent Pub. No. WO 2006/095951, andU.S. Pat. Application Pub. No. US 2011/0037057, which are herebyincorporated by reference in their entireties, describe the making ofdeuterium-substituted organometallic complexes. Further reference ismade to Ming Yan, et al., Tetrahedron 2015, 71, 1425-30 and Atzrodt etal., Angew. Chem. Int. Ed. (Reviews) 2007, 46, 7744-65, which areincorporated by reference in their entireties, describe the deuterationof the methylene hydrogens in benzyl amines and efficient pathways toreplace aromatic ring hydrogens with deuterium, respectively.

It is to be understood that when a molecular fragment is described asbeing a substituent or otherwise attached to another moiety, its namemay be written as if it were a fragment (e.g. phenyl, phenylene,naphthyl, dibenzofuryl) or as if it were the whole molecule (e.g.benzene, naphthalene, dibenzofuran). As used herein, these differentways of designating a substituent or attached fragment are considered tobe equivalent.

A compound having the following Formula I is disclosed:

In Formula I, R represents an adjacent di-substitution having thefollowing formula fused to ring A:

where the bonds with wave lines represent the bonds connected to twoadjacent carbon atoms from the ring A. R^(A), and R^(C) eachindependently represents mono, di, tri, or tetra substitution, or nosubstitution. R^(B) represents mono, or di substitution, or nosubstitution. L¹ and L² each independently represents a direct bond oran organic linker. G¹ and G² are each independently selected from thegroup consisting of aryl, heteroaryl, substituted variants thereof, andcombination thereof; where at least one of G¹ and G² comprises astructure having the formula:

where X¹-X⁸ are each independently selected from the group consisting ofC and N; where at least one of X¹-X⁸ is N; where the maximum number of Natoms in a ring can connect to each other is two; where R^(A), R^(B),R^(C), R^(D), and R^(E) are each independently selected from the groupconsisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl,heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl,alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl,carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl,sulfonyl, phosphino, and combinations thereof; and where any twosubstituents may be joined or fused together to form a ring.

In some embodiments of the compound, R^(A), R^(B), R^(C), R^(D), andR^(E) are each independently selected from the group consisting ofhydrogen, deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy,aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl,heteroaryl, nitrile, isonitrile, sulfanyl, and combinations thereof.

In some embodiments, one of X¹-X⁸ is N, and the remaining X¹-X⁸ are C.In some embodiments, two of X¹-X⁸ is N, and the remaining X¹-X⁸ are C.In such case, the two N atoms can be on the same ring or on twodifferent rings.

In some embodiments, L¹and L² are independently selected from the groupconsisting of direct bond, aryl, substituted aryl, heteroaryl, andsubstituted heteroaryl.

In some embodiments, G¹ and G² each independently comprises a structureselected from the group consisting of phenyl, biphenyl, terphenyl,naphthalene, triphenylene, dibenzothiophene, dibenzofuran, carbazole,azacarbazole, imidazole, pyrazole, triazole, pyrimidine, quinazoline,quinoxaline and triazine.

In some embodiments, L¹ and L² are each independently selected from thegroup consisting of direct bond, aryl, and heteroaryl.

In some embodiments, the compound is selected from the group consistingof:

and wherein R′ has the same definition as R^(A), R^(B), R^(C), R^(D),and R^(E).

In some embodiments, the compound is selected from the group consistingof:

An OLED comprising an anode, a cathode, and an organic layer, disposedbetween the anode and the cathode, where the organic layer comprising acompound having a formula:

is disclosed. In Formula I, R represents an adjacent di-substitutionhaving the following formula fused to ring A:

where the bonds with wave lines represent the bonds connected to twoadjacent carbon atoms from the ring A. R^(A), and R^(C) eachindependently represents mono, di, tri, or tetra substitution, or nosubstitution. R^(B) represents mono, or di substitution, or nosubstitution. L¹ and L² each independently represents a direct bond oran organic linker. G¹ and G² are each independently selected from thegroup consisting of aryl, heteroaryl, substituted variants thereof, andcombinations thereof. At least one of G¹ and G² comprises a structurehaving the formula:

where X¹-X⁸ are each independently selected from the group consisting ofC and N; where at least one of X¹-X⁸ is N; where the maximum number of Natoms in a ring that can connect to each other is two; where R^(A),R^(B), R^(C), R^(D), and R^(E) are each independently selected from thegroup consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl,heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl,alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl,carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl,sulfonyl, phosphino, and combinations thereof; and where any twosubstituents may be joined or fused together to form a ring.

In some embodiments of the OLED, the organic layer is an emissive layerand the compound of Formula I is a host.

In some embodiments of the OLED, the organic layer further comprises aphosphorescent emissive dopant; wherein the emissive dopant is atransition metal complex having at least one ligand or part of theligand if the ligand is more than bidentate, selected from the groupconsisting of:

where each X¹ to X¹³ are independently selected from the groupconsisting of carbon and nitrogen;

where X is selected from the group consisting of BR′, NR′, PR′, O, S,Se, C═O, S═O, SO₂, CR′R″, SiR′R″, and GeR′R″;

where R′ and R″ are optionally fused or joined to form a ring;

where each R_(a), R_(b), R_(c), and R_(d) may represent from monosubstitution to the possible maximum number of substitution, or nosubstitution;

where R′, R″, R_(a), R_(b), R_(c), and R_(d) are each independentlyselected from the group consisting of hydrogen, deuterium, halogen,alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy,aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl,aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile,isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinationsthereof; and

where any two adjacent substituents of R_(a), R_(b), R_(c), and R_(d)are optionally fused or joined to form a ring or form a multidentateligand.

In some embodiments of the OLED, the organic layer is a charge carrierblocking layer and the compound of claim 1 is a charge carrier blockingmaterial in the organic layer.

In some embodiments of the OLED, the organic layer is a charge carriertransporting layer and the compound of claim 1 is a charge carriertransporting material in the organic layer.

A consumer product comprising the OLED comprising an anode, a cathode,and an organic layer, disposed between the anode and the cathode, wherethe organic layer comprises a compound having the formula:

is disclosed. In Formula I, R represents an adjacent di-substitutionhaving the following formula fused to ring A:

where the bonds with wave lines represent the bonds connected to twoadjacent carbon atoms from the ring A. R^(A), and R^(C) eachindependently represents mono, di, tri, or tetra substitution, or nosubstitution. R^(B) represents mono, or di substitution, or nosubstitution. L¹ and L² each independently represents a direct bond oran organic linker. G¹ and G² are each independently selected from thegroup consisting of aryl, heteroaryl, substituted variants thereof, andcombinations thereof. At least one of G¹ and G² comprises a structurehaving the formula:

where X¹-X⁸ are each independently selected from the group consisting ofC and N; where at least one of X¹-X⁸ is N; where the maximum number of Natoms in a ring that can connect to each other is two; where R^(A),R^(B), R^(C), R^(D), and R^(E) are each independently selected from thegroup consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl,heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl,alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl,carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl,sulfonyl, phosphino, and combinations thereof; and where any twosubstituents may be joined or fused together to form a ring.

In some embodiments, the OLED has one or more characteristics selectedfrom the group consisting of being flexible, being rollable, beingfoldable, being stretchable, and being curved. In some embodiments, theOLED is transparent or semi-transparent. In some embodiments, the OLEDfurther comprises a layer comprising carbon nanotubes.

In some embodiments, the OLED further comprises a layer comprising adelayed fluorescent emitter. In some embodiments, the OLED comprises aRGB pixel arrangement or white plus color filter pixel arrangement. Insome embodiments, the OLED is a mobile device, a hand held device, or awearable device. In some embodiments, the OLED is a display panel havingless than 10 inch diagonal or 50 square inch area. In some embodiments,the OLED is a display panel having at least 10 inch diagonal or 50square inch area. In some embodiments, the OLED is a lighting panel.

The emitter dopants can be phosphorescent dopants and/or fluorescentdopants and the novel compounds of the present disclosure can be used asa host for both phosphorescent dopants and fluorescent dopants.

An emissive region in an organic light emitting device is alsodisclosed. The emissive region comprising a compound having thefollowing Formula I is disclosed:

In Formula I, R represents an adjacent di-substitution having thefollowing formula fused to ring A:

where the bonds with wave lines represent the bonds connected to twoadjacent carbon atoms from the ring A. R^(A), and R^(C) eachindependently represents mono, di, tri, or tetra substitution, or nosubstitution. R^(B) represents mono, or di substitution, or nosubstitution. L¹ and L² each independently represents a direct bond oran organic linker. G¹ and G² are each independently selected from thegroup consisting of aryl, heteroaryl, substituted variants thereof, andcombination thereof; where at least one of G¹ and G² comprises astructure having the formula:

where X¹-X⁸ are each independently selected from the group consisting ofC and N; where at least one of X¹-X⁸ is N; where the maximum number of Natoms in a ring can connect to each other is two; where R^(A), R^(B),R^(C), R^(D), and R^(E) are each independently selected from the groupconsisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl,heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl,alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl,carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl,sulfonyl, phosphino, and combinations thereof; and where any twosubstituents may be joined or fused together to form a ring.

In the emissive region, the compound is a host.

In some embodiments, the emissive region further comprises aphosphorescent emissive dopant; wherein the emissive dopant is atransition metal complex having at least one ligand or part of theligand if the ligand is more than bidentate selected from the groupconsisting of:

wherein each X¹ to X¹³ are independently selected from the groupconsisting of carbon and nitrogen;

wherein Xis selected from the group consisting of BR′, NR′, PR′, O, S,Se, C═O, S═O, SO₂, CR′R″, SiR′R″, and GeR′R″;

wherein R′ and R″ are optionally fused or joined to form a ring;

wherein each R_(a), R_(b), R_(c), and R_(d) may represent from monosubstitution to the possible maximum number of substitution, or nosubstitution;

wherein R′, R″, R_(a), R_(b), R_(c), and R_(d) are each independentlyselected from the group consisting of hydrogen, deuterium, halogen,alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy,aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl,aryl, heteroaryl, acyl, carboxylic acids, ether, ester, nitrile,isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinationsthereof; and

wherein any two substituents of R_(a), R_(b), R_(c), and R_(d) areoptionally fused or joined to form a ring or form a multidentate ligand.

According to another aspect, a formulation comprising the compounddescribed herein is also disclosed.

The OLED disclosed herein can be incorporated into one or more of aconsumer product, an electronic component module, and a lighting panel.

In yet another aspect of the present disclosure, a formulation thatcomprises the novel compound disclosed herein is described. Theformulation can include one or more components selected from the groupconsisting of a solvent, a host, a hole injection material, holetransport material, electron blocking material, hole blocking material,and an electron transport layer material, disclosed herein.

Combination with Other Materials

The materials described herein as useful for a particular layer in anorganic light emitting device may be used in combination with a widevariety of other materials present in the device. For example, emissivedopants disclosed herein may be used in conjunction with a wide varietyof hosts, transport layers, blocking layers, injection layers,electrodes and other layers that may be present. The materials describedor referred to below are non-limiting examples of materials that may beuseful in combination with the compounds disclosed herein, and one ofskill in the art can readily consult the literature to identify othermaterials that may be useful in combination.

Conductivity Dopants:

A charge transport layer can be doped with conductivity dopants tosubstantially alter its density of charge carriers, which will in turnalter its conductivity. The conductivity is increased by generatingcharge carriers in the matrix material, and depending on the type ofdopant, a change in the Fermi level of the semiconductor may also beachieved. Hole-transporting layer can be doped by p-type conductivitydopants and n-type conductivity dopants are used in theelectron-transporting layer.

Non-limiting examples of the conductivity dopants that may be used in anOLED in combination with materials disclosed herein are exemplifiedbelow together with references that disclose those materials:EP01617493, EP01968131, EP2020694, EP2684932, US20050139810,US20070160905, US20090167167, US2010288362, WO06081780, WO2009003455,WO2009008277, WO2009011327, WO2014009310, US2007252140, US2015060804,US20150123047, and US2012146012.

HIL/HTL:

A hole injecting/transporting material to be used in the presentinvention is not particularly limited, and any compound may be used aslong as the compound is typically used as a hole injecting/transportingmaterial. Examples of the material include, but are not limited to: aphthalocyanine or porphyrin derivative; an aromatic amine derivative; anindolocarbazole derivative; a polymer containing fluorohydrocarbon; apolymer with conductivity dopants; a conducting polymer, such asPEDOT/PSS; a self-assembly monomer derived from compounds such asphosphonic acid and silane derivatives; a metal oxide derivative, suchas MoO_(x); a p-type semiconducting organic compound, such as1,4,5,8,9,12-Hexaazatriphenylenehexacarbonitrile; a metal complex, and across-linkable compounds.

Examples of aromatic amine derivatives used in HIL or HTL include, butare not limited to the following general structures:

Each of Ar¹ to Ar⁹ is selected from the group consisting of aromatichydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl,triphenylene, naphthalene, anthracene, phenalene, phenanthrene,fluorene, pyrene, chrysene, perylene, and azulene; the group consistingof aromatic heterocyclic compounds such as dibenzothiophene,dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran,benzothiophene, benzoselenophene, carbazole, indolocarbazole,pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole,oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole,pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine,oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine,benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline,cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine,pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine,benzofuropyridine, furodipyridine, benzothienopyridine,thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine;and the group consisting of 2 to 10 cyclic structural units which aregroups of the same type or different types selected from the aromatichydrocarbon cyclic group and the aromatic heterocyclic group and arebonded to each other directly or via at least one of oxygen atom,nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom,chain structural unit and the aliphatic cyclic group. Each Ar may beunsubstituted or may be substituted by a substituent selected from thegroup consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl,heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl,cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylicacids, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl,phosphino, and combinations thereof.

In one aspect, Ar¹ to Ar⁹ is independently selected from the groupconsisting of:

wherein k is an integer from 1 to 20; X¹⁰¹ to X¹⁰⁸ is C (including CH)or N; Z¹⁰¹ is NAr¹, O, or S; Ar¹ has the same group defined above.

Examples of metal complexes used in HIL or HTL include, but are notlimited to the following general formula:

wherein Met is a metal, which can have an atomic weight greater than 40;(Y¹⁰¹-Y¹⁰²) is a bidentate ligand, Y¹⁰¹ and Y¹⁰² are independentlyselected from C, N, O, P, and S; L¹⁰¹ is an ancillary ligand; k′ is aninteger value from 1 to the maximum number of ligands that may beattached to the metal; and k′+k″ is the maximum number of ligands thatmay be attached to the metal.

In one aspect, (Y¹⁰¹-Y¹⁰²) is a 2-phenylpyridine derivative. In anotheraspect, (Y¹⁰¹-Y¹⁰²) is a carbene ligand. In another aspect, Met isselected from Ir, Pt, Os, and Zn. In a further aspect, the metal complexhas a smallest oxidation potential in solution vs. Fc⁺/Fc couple lessthan about 0.6 V.

Non-limiting examples of the HIL and HTL materials that may be used inan OLED in combination with materials disclosed herein are exemplifiedbelow together with references that disclose those materials:CN102702075, DE102012005215, EP01624500, EP01698613, EP01806334,EP01930964, EP01972613, EP01997799, EP02011790, EP02055700, EP02055701,EP1725079, EP2085382, EP2660300, EP650955, JP07-073529, JP2005112765,JP2007091719, JP2008021687, JP2014-009196, KR20110088898, KR20130077473,TW201139402, US06517957, US20020158242, US20030162053, US20050123751,US20060182993, US20060240279, US20070145888, US20070181874,US20070278938, US20080014464, US20080091025, US20080106190,US20080124572, US20080145707, US20080220265, US20080233434,US20080303417, US2008107919, US20090115320, US20090167161, US2009066235,US2011007385, US20110163302, US2011240968, US2011278551, US2012205642,US2013241401, US20140117329, US2014183517, U.S. Pat. No. 5,061,569, U.S.Pat. No. 5,639,914, WO05075451, WO07125714, WO08023550, WO08023759,WO2009145016, WO2010061824, WO2011075644, WO2012177006, WO2013018530,WO2013039073, WO2013087142, WO2013118812, WO2013120577, WO2013157367,WO2013175747, WO2014002873, WO2014015935, WO2014015937, WO2014030872,WO2014030921, WO2014034791, WO2014104514, WO2014157018,

EBL:

An electron blocking layer (EBL) may be used to reduce the number ofelectrons and/or excitons that leave the emissive layer. The presence ofsuch a blocking layer in a device may result in substantially higherefficiencies, and/or longer lifetime, as compared to a similar devicelacking a blocking layer. Also, a blocking layer may be used to confineemission to a desired region of an OLED. In some embodiments, the EBLmaterial has a higher LUMO (closer to the vacuum level) and/or highertriplet energy than the emitter closest to the EBL interface. In someembodiments, the EBL material has a higher LUMO (closer to the vacuumlevel) and/or higher triplet energy than one or more of the hostsclosest to the EBL interface. In one aspect, the compound used in EBLcontains the same molecule or the same functional groups used as one ofthe hosts described below.

Additional Hosts:

The light emitting layer of the organic EL device of the presentinvention preferably contains at least a metal complex as light emittingdopant material, and may contain one or more additional host materialsusing the metal complex as a dopant material. Examples of the hostmaterial are not particularly limited, and any metal complexes ororganic compounds may be used as long as the triplet energy of the hostis larger than that of the dopant. Any host material may be used withany dopant so long as the triplet criteria is satisfied.

Examples of metal complexes used as host are preferred to have thefollowing general formula:

wherein Met is a metal; (Y¹⁰³-Y¹⁰⁴) is a bidentate ligand, Y¹⁰³ and Y¹⁰⁴are independently selected from C, N, O, P, and S; L¹⁰¹ is an anotherligand; k′ is an integer value from 1 to the maximum number of ligandsthat may be attached to the metal; and k′+k″ is the maximum number ofligands that may be attached to the metal.

In one aspect, the metal complexes are:

wherein (O—N) is a bidentate ligand, having metal coordinated to atoms Oand N.

In another aspect, Met is selected from Ir and Pt. In a further aspect,(Y¹⁰³-Y¹⁰⁴) is a carbene ligand.

Examples of other organic compounds used as additional host are selectedfrom the group consisting of aromatic hydrocarbon cyclic compounds suchas benzene, biphenyl, triphenyl, triphenylene, naphthalene, anthracene,phenalene, phenanthrene, fluorene, pyrene, chrysene, perylene, azulene;group consisting aromatic heterocyclic compounds such asdibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene,benzofuran, benzothiophene, benzoselenophene, carbazole,indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole,triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole,thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine,oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole,indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline,isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine,phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine,phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine,thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine;and group consisting 2 to 10 cyclic structural units which are groups ofthe same type or different types selected from the aromatic hydrocarboncyclic group and the aromatic heterocyclic group and are bonded to eachother directly or via at least one of oxygen atom, nitrogen atom, sulfuratom, silicon atom, phosphorus atom, boron atom, chain structural unitand the aliphatic cyclic group. Wherein each group is furthersubstituted by a substituent selected from the group consisting ofhydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl,heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl,cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylicacids, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl,phosphino, and combinations thereof.

In one aspect, host compound contains at least one of the followinggroups in the molecule:

wherein R¹⁰¹ is selected from the group consisting of hydrogen,deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl,arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl,heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acids, ether,ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, andcombinations thereof, when it is aryl or heteroaryl, it has the similardefinition as Ar's mentioned above. k is an integer from 0 to 20 or 1 to20. X¹⁰¹ to X¹⁰⁸ are independently selected from C (including CH) or N.Z¹⁰¹ and Z¹⁰² are independently selected from NR¹⁰¹, O, or S.

Non-limiting examples of the additional host materials that may be usedin an OLED in combination with the host compound disclosed herein areexemplified below together with references that disclose thosematerials: EP2034538, EP2034538A, EP2757608, JP2007254297,KR20100079458, KR20120088644, KR20120129733, KR20130115564, TW201329200,US20030175553, US20050238919, US20060280965, US20090017330,US20090030202, US20090167162, US20090302743, US20090309488,US20100012931, US20100084966, US20100187984, US2010187984, US2012075273,US2012126221, US2013009543, US2013105787, US2013175519, US2014001446,US20140183503, US20140225088, US2014034914, U.S. Pat. No. 7,154,114,WO2001039234, WO2004093207, WO2005014551, WO2005089025, WO2006072002,WO2006114966, WO2007063754, WO2008056746, WO2009003898, WO2009021126,WO2009063833, WO2009066778, WO2009066779, WO2009086028, WO2010056066,WO2010107244, WO2011081423, WO2011081431, WO2011086863, WO2012128298,WO2012133644, WO2012133649, WO2013024872, WO2013035275, WO2013081315,WO2013191404, WO2014142472, US20170263869, US20160163995, U.S. Pat. No.9,466,803.

Emitter:

An emitter example is not particularly limited, and any compound may beused as long as the compound is typically used as an emitter material.Examples of suitable emitter materials include, but are not limited to,compounds which can produce emissions via phosphorescence, fluorescence,thermally activated delayed fluorescence, i.e., TADF (also referred toas E-type delayed fluorescence; see, e.g., U.S. application Ser. No.15/700,352, which is hereby incorporated by reference in its entirety),triplet-triplet annihilation, or combinations of these processes.

Non-limiting examples of the emitter materials that may be used in anOLED in combination with materials disclosed herein are exemplifiedbelow together with references that disclose those materials:CN103694277, CN1696137, EB01238981, EP01239526, EP01961743, EP1239526,EP1244155, EP1642951, EP1647554, EP1841834, EP1841834B, EP2062907,EP2730583, JP2012074444, JP2013110263, JP4478555, KR1020090133652,KR20120032054, KR20130043460, TW201332980, US06699599, US06916554,US20010019782, US20020034656, US20030068526, US20030072964,US20030138657, US20050123788, US20050244673, US2005123791, US2005260449,US20060008670, US20060065890, US20060127696, US20060134459,US20060134462, US20060202194, US20060251923, US20070034863,US20070087321, US20070103060, US20070111026, US20070190359,US20070231600, US2007034863, US2007104979, US2007104980, US2007138437,US2007224450, US2007278936, US20080020237, US20080233410, US20080261076,US20080297033, US200805851, US2008161567, US2008210930, US20090039776,US20090108737, US20090115322, US20090179555, US2009085476, US2009104472,US20100090591, US20100148663, US20100244004, US20100295032,US2010102716, US2010105902, US2010244004, US2010270916, US20110057559,US20110108822, US20110204333, US2011215710, US2011227049, US2011285275,US2012292601, US20130146848, US2013033172, US2013165653, US2013181190,US2013334521, US20140246656, US2014103305, U.S. Pat. No. 6,303,238, U.S.Pat. No. 6,413,656, U.S. Pat. No. 6,653,654, U.S. Pat. No. 6,670,645,U.S. Pat. No. 6,687,266, U.S. Pat. No. 6,835,469, U.S. Pat. No.6,921,915, U.S. Pat. No. 7,279,704, U.S. Pat. No. 7,332,232, U.S. Pat.No. 7,378,162, U.S. Pat. No. 7,534,505, U.S. Pat. No. 7,675,228, U.S.Pat. No. 7,728,137, U.S. Pat. No. 7,740,957, U.S. Pat. No. 7,759,489,U.S. Pat. No. 7,951,947, U.S. Pat. No. 8,067,099, U.S. Pat. No.8,592,586, U.S. Pat. No. 8,871,361, WO06081973, WO06121811, WO07018067,WO07108362, WO07115970, WO07115981, WO08035571, WO2002015645,WO2003040257, WO2005019373, WO2006056418, WO2008054584, WO2008078800,WO2008096609, WO2008101842, WO2009000673, WO2009050281, WO2009100991,WO2010028151, WO2010054731, WO2010086089, WO2010118029, WO2011044988,WO2011051404, WO2011107491, WO2012020327, WO2012163471, WO2013094620,WO2013107487, WO2013174471, WO2014007565, WO2014008982, WO2014023377,WO2014024131, WO2014031977, WO2014038456, WO2014112450,

HBL:

A hole blocking layer (HBL) may be used to reduce the number of holesand/or excitons that leave the emissive layer. The presence of such ablocking layer in a device may result in substantially higherefficiencies and/or longer lifetime as compared to a similar devicelacking a blocking layer. Also, a blocking layer may be used to confineemission to a desired region of an OLED. In some embodiments, the HBLmaterial has a lower HOMO (further from the vacuum level) and or highertriplet energy than the emitter closest to the HBL interface. In someembodiments, the HBL material has a lower HOMO (further from the vacuumlevel) and or higher triplet energy than one or more of the hostsclosest to the HBL interface.

In one aspect, compound used in HBL contains the same molecule or thesame functional groups used as host described above.

In another aspect, compound used in HBL contains at least one of thefollowing groups in the molecule:

wherein k is an integer from 1 to 20; L¹⁰¹ is an another ligand, k′ isan integer from 1 to 3.

ETL:

Electron transport layer (ETL) may include a material capable oftransporting electrons. Electron transport layer may be intrinsic(undoped), or doped. Doping may be used to enhance conductivity.Examples of the ETL material are not particularly limited, and any metalcomplexes or organic compounds may be used as long as they are typicallyused to transport electrons.

In one aspect, compound used in ETL contains at least one of thefollowing groups in the molecule:

wherein R¹⁰¹ is selected from the group consisting of hydrogen,deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl,arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl,heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acids, ether,ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, andcombinations thereof, when it is aryl or heteroaryl, it has the similardefinition as Ar's mentioned above. Ar¹ to Ar³ has the similardefinition as Ar's mentioned above. k is an integer from 1 to 20. X¹⁰¹to X¹⁰⁸ is selected from C (including CH) or N.

In another aspect, the metal complexes used in ETL include, but are notlimited to the following general formula:

wherein (O—N) or (N—N) is a bidentate ligand, having metal coordinatedto atoms O, N or N, N; L¹⁰¹ is another ligand; k′ is an integer valuefrom 1 to the maximum number of ligands that may be attached to themetal.

Non-limiting examples of the ETL materials that may be used in an OLEDin combination with materials disclosed herein are exemplified belowtogether with references that disclose those materials: CN103508940,EP01602648, EP01734038, EP01956007, JP2004-022334, JP2005149918,JP2005-268199, KR0117693, KR20130108183, US20040036077, US20070104977,US2007018155, US20090101870, US20090115316, US20090140637,US20090179554, US2009218940, US2010108990, US2011156017, US2011210320,US2012193612, US2012214993, US2014014925, US2014014927, US20140284580,U.S. Pat. No. 6,656,612, U.S. Pat. No. 8,415,031, WO2003060956,WO2007111263, WO2009148269, WO2010067894, WO2010072300, WO2011074770,WO2011105373, WO2013079217, WO2013145667, WO2013180376, WO2014104499,WO2014104535,

Charge Generation Layer (CGL)

In tandem or stacked OLEDs, the CGL plays an essential role in theperformance, which is composed of an n-doped layer and a p-doped layerfor injection of electrons and holes, respectively. Electrons and holesare supplied from the CGL and electrodes. The consumed electrons andholes in the CGL are refilled by the electrons and holes injected fromthe cathode and anode, respectively; then, the bipolar currents reach asteady state gradually. Typical CGL materials include n and pconductivity dopants used in the transport layers.

In any above-mentioned compounds used in each layer of the OLED device,the hydrogen atoms can be partially or fully deuterated. Thus, anyspecifically listed substituent, such as, without limitation, methyl,phenyl, pyridyl, etc. encompasses undeuterated, partially deuterated,and fully deuterated versions thereof. Similarly, classes ofsubstituents such as, without limitation, alkyl, aryl, cycloalkyl,heteroaryl, etc. also encompass undeuterated, partially deuterated, andfully deuterated versions thereof.

Experimental SYNTHETIC EXAMPLES Synthesis of Compound Cmp 84

To a 1 Liter flask, 9H-pyrido[2,3-b]indole (10.00 g, 59.5 mmol),potassium phosphate (37.9 g, 178 mmol), copper(I) iodide (11.32 g, 59.5mmol), Iodobenzene (8.65 ml, 77 mmol), 1,2-diaminocyclohexane (7.30 ml,59.5 mmol), and toluene (300 ml) were added. The reaction mixture washeated to reflux overnight (approx. 16 hours). The reaction mixture wascooled, filtered through a plug of Celite and washed withdichloromethane (DCM). The filtrate was concentrated and resultingresidue was purified via column chromatography (EtOAc/heptane) to give9-phenyl-9Hpyrido[2,3-b]indole as a white solid (13.57 g, 93% yield).

To a 500 mL flask, 9-phenyl-9H-pyrido[2,3-b]indole (13.57 g, 55 5 mmol)and acetic acid (168 ml) were added. N-bromosuccinimide (10.88 g, 61.1mmol) was then added and the reaction mixture was stirred at roomtemperature. After overnight (approx. 16 hours) stirring, the reactionmixture was neutralized with an aqueous NaOH solution and stirred for 2hours. The resulting white solid was collected via suction filtrationand purified by column chromatography (DCM/heptane) to obtain 11.12 g(62% yield) of 6-bromo-9-phenyl-9H-pyrido[2,3-b]indole as a white solid.

To a 250 mL flask under nitrogen,5-([1,1′-biphenyl]-4-yl)-5,8-dihydroindolo[2,3-c]carbazole (4.00 g, 9.79mmol), 6-bromo-9-phenyl-9H-pyrido[2,3-b]indole (4.11 g, 12.73 mmol),sodium tert-butoxide (2.353 g, 24.48 mmol), Pd₂(dba)₃ (0.448 g, 0.490mmol), dicyclohexyl(2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl)phosphane(0.402 g, 0.979 mmol), and xylenes (49.0 ml) were added. The flask wasevacuated and backfilled with nitrogen. Evacuation and back-fillprocedure was repeated twice. The reaction mixture was refluxed for 74hours. Upon completion, the reaction mixture was filtered through a padof Celite and washed with DCM. The solvent was removed by rotaryevaporation and the residue was purified by column chromatography usingheptane and dichloromethane. Further trituration with methanol gave5-([1,1′-biphenyl]-4-yl)-8-(9-phenyl-9H-pyrido[2,3-b[indol-6-yl)-5,8-dihydroindolo[2,3-c]carbazoleCmp 84 (4.4 g, 68% yield) as a white powder.

Synthesis of Cmp 81

To a 3-liter flask, 2-chloro-3-nitropyridine (45 g, 284 mmol),phenylboronic acid (41.5 g, 341 mmol), sodium carbonate (60.2 g, 568mmol), Pd(Ph₃P)₄ (13.12 g, 11.35 mmol),1,2-dimethoxyethane (811 ml), andwater (324 ml) were added. The flask was evacuated and backfilled withnitrogen. Evacuation and back-fill procedure was repeated twice. Thereaction mixture was then refluxed overnight (approx. 16 hours). Aftercompletion, the reaction mixture was extracted with dichloromethane andconcentrated. Resulting residue was purified by column chromatography(DCM/heptane) to afford 45.1 g (79.2% yield) of3-nitro-2-phenylpyridine.

To a 4-necked 3-liter flask, 3-nitro-2-phenylpyridine (50 g, 250 mmol)and 1,2-dichlorobenzene (555 ml) were added. Triphenylphosphine (197 g,749 mmol) was then added and reaction mixture was refluxed for 20 hours.After completion, 1,2-dichlorobenzene was removed via vacuumdistillation and crude residue was purified by column chromatographyfollowed by trituration with diethyl ether to obtain 24.5 g (55.4%yield) of 5H-pyrido[3,2-b[indole

500 mL flask was charged with 5H-pyrido [3,2-b]indole (14 g, 83 mmol),potassium phosphate (53.0 g, 250 mmol), toluene (416 ml), iodobenzene(12.06 ml, 108 mmol), copper(I)iodide (15.85 g, 83 mmol) andcyclohexane-1,2-diamine (10.21 ml, 83 mmol). The flask was evacuated andbackfilled with nitrogen and then refluxed overnight (approx. 16 hours).The reaction mixture was cooled, filtered through a plug of Celite andwashed with DCM. The filtrate was concentrated and resulting residue waspurified by silica gel column chromatography (DCM/heptane) to obtain5-(3-bromophenyl)-5H-pyrido[3,2-b]indole (11.7 g, 76% yield).

To a 250 mL flask, 5-phenyl-5H-pyrido[3,2-b]indole (4.89 g, 20.0 mmol)and acetic acid (60 ml). After stirring for 10 min, N-bromosuccinimide(3.92 g, 22.00 mmol) was added into reaction mixture and stirred for 2hours at room temperature. The reaction mixture was then neutralizedwith an aqueous NaOH solution and stirred for 1 hour. The solid wasfiltered, washed with water, dried and then triturated with diethylether/heptane (1:1) to provide 8-bromo-5-phenyl-5H-pyrido[3,2-b]indole(5.50 g, 85% yield) as an off-white solid.

A 250 mL 3-neck flask was charged with8-bromo-5-phenyl-5H-pyrido[3,2-b]indole (4.04 g, 12.50 mmol),5-([1,1′-biphenyl]-4-yl)-5,8-dihydroindolo [2,3-c]carbazole (4.09 g,10.00 mmol), sodium tert-butoxide (2.403 g, 25.00 mmol),dicyclohexyl(2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl)phosphane (SPhos)(0.411 g, 1.000 mmol), Pd₂(dba)₃ (0.458 g, 0.500 mmol) and Xylene (50.0ml). The flask was evacuated and backfilled with nitrogen. Evacuationand back-fill procedure was repeated twice. The reaction mixture wasthen refluxed for 72 hours. After completion, reaction mixture waspassed through a short plug of silica and washed with hot chloroform.The crude solid was triturated with dichloromethane/methanol (1:9) toprovide5-([1,1′-biphenyl]-4-yl)-8-(5-phenyl-5H-pyrido[3,2-b]indol-8-yl)-5,8-dihydroindolo[2,3-c]carbazoleCmp 81(6.50 g, 99% yield) as a white solid.

Synthesis of Cmpd 173

To a 250 mL flask, 9H-pyrido[2,3-b]indole (3.85 g, 22.89 mmol),potassium phosphate (14.58 g, 68.7 mmol), copper(I) iodide (4.36 g,22.89 mmol), 1,3-dibromobenzene (5.53 ml, 45.8 mmol),1,2-diaminocyclohexane (2.81 ml, 22.89 mmol) and toluene (114 ml) wereadded. The reaction mixture was stirred and heated to reflux overnight(approx. 16 hours). Upon completion, the reaction mixture was filteredthrough a pad of Celite and washed with DCM. The solvent was removed byrotary evaporation and crude residue was purified by columnchromatography (DCM/heptane). Further trituration with MeOH gave 6.9 g(94%) of 9-(3-bromophenyl)-9H-pyrido[2,3-b]indole as a white solid.

A 250 mL flask was charged with5-([1,1′-biphenyl]-4-yl)-5,8-dihydroindolo[2,3-c]carbazole(4.00 g, 9.79mmol), 9-(3-bromophenyl)-9H-pyrido[2,3-b]indole (5.01 g, 15.50 mmol),sodium tert-butoxide (2.35 g, 24.45 mmol),dicyclohexyl(2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl)phosphane (0.402 g,0.979 mmol), Pd₂(dba)₃ (0.448 g, 0.489 mmol), and xylene (50 ml). Theflask was evacuated and backfilled with nitrogen. Evacuation andback-fill procedure was repeated twice. The reaction mixture was thenrefluxed for 72 hours. Upon completion, reaction mixture was filteredthrough a pad of Celite and washed with DCM. The solvent was removed byrotary evaporation and the residue was purified by column chromatographyusing heptane and dichloromethane. Trituration with acetone/methanolafforded5-(3-(9H-pyrido[2,3-b]indol-9-yl)phenyl)-8-([1,1′-biphenyl]-4-yl)-5,8-dihydroindolo[2,3-c]carbazoleCmp 173 (6.2 g, 98% yield) as a white powder.

Synthesis of Cmp 174

A 500 mL 3-necked flask was charged with 9H-pyrido[3,4-b]indole (6 g,35.7 mmol), 1,3-dibromobenzene (10.1 g, 42.8 mmol), potassium phosphate(22.72 g, 107 mmol), copper(I) iodide (6.79 g, 35.7 mmol),cyclohexane-1,2-diamine (8.75 ml, 71.3 mmol) and toluene (200 ml). Theflask was evacuated and backfilled with nitrogen. The reaction mixturewas then heated to reflux for 24 hours. After completion, the reactionmixture was filtered through a pad of Celite and washed with DCM. Thesolvent was removed by rotary evaporation and the residue was purifiedby column chromatography (10% ethyl acetate/heptane) to obtain 7.5 g(65%) of 9-(3-bromophenyl)-9H-pyrido[3,4-b]indole as a white solid.

5-([1,1′-biphenyl]-4-yl)-5,8-dihydroindolo[2,3-c]carbazole (5 g, 12.24mmol), 9-(3-bromophenyl)-9H-pyrido[3,4-b]indole (4.75 g, 14.69 mmol),sodium tert-butoxide (3.53 g, 36 7 mmol),dicyclohexyl(2′,6′-dimethoxy-[1,1′-biphenyl]-2-yl)phosphane (0.603 g,1.469 mmol), Pd₂(dba)₃ (0.673 g, 0.734 mmol) and xylene (70 ml) wereadded into a 250 mL 3-necked flask. The flask was evacuated andbackfilled with nitrogen. Evacuation and back-fill procedure wasrepeated twice. The reaction mixture was then refluxed for 72 hours.Upon completion, the reaction mixture was filtered through a pad ofCelite and washed with DCM. The solvent was removed by rotaryevaporation and the residue was purified by column chromatography usingheptane and dichloromethane. Further trituration withdichloromethane/methanol gave 7.2 g (96% yield) of the5-(3-(9H-pyrido[3,4-b]indol-9-yl)phenyl)-8-([1,1′-biphenyl]-4-yl)-5,8-dihydroindolo[2,3-c]carbazoleCmp 174 as a white powder.

DEVICE EXAMPLES

All example devices were fabricated by high vacuum (<10⁻⁷ Torr) thermalevaporation. The anode electrode was 750 Å of indium tin oxide (ITO).The cathode consisted of 10 Å of Liq (8-hydroxyquinoline lithium)followed by 1,000 Å of Al. All devices were encapsulated with a glasslid sealed with an epoxy resin in a nitrogen glove box (<1 ppm of H₂Oand O₂) immediately after fabrication with a moisture getterincorporated inside the package. The organic stack of the deviceexamples consisted of sequentially, from the ITO Surface: 100 Å ofHAT-CN as the hole injection layer (HIL); 450 Å of HTM as a holetransporting layer (HTL); emissive layer (EML) with thickness 400 Åcontaining h-host (an inventive compound or a comparativecompound):e-host (compound H2) and a green emitter (compound Gl) wherethe h-host was 40 wt. % and the e-host was 10 wt. % with respect to thegreen emitter; 350 Å of Liq (8-hydroxyquinoline lithium) doped with 40%of ETM as the electron transport layer (ETL). Compound Cmp 84 was usedas the h-host in the Example 1 device. Compound H001 was used as theh-host in the comparative example device CE1. The device structures aresummarized in Table 1. As used herein, h-host refers to holetransporting host and e-host refers to electron transporting host.

The chemical structures of the materials used in the devices are shownbelow.

Upon fabrication the EL and JVL performance of the devices weremeasured. The results are summariezed in Table 2.

TABLE 1 Device example layer structure Layer in the Device MaterialThickness [Å] Anode ITO 750 HIL HAT-CN 100 HTL HTM 450 Green EML Host:H240%: GD1 10% 400 ETL Liq:ETM 40% 350 EIL Liq 10 Cathode Al 1,000

TABLE 2 Performance of Devices Example 1 and CE1 At 1,000 nits HostVoltage EQE Example Material Color [V] [%] Example 1 Cmp 84 green 2.8 22CE 1 H001 green 2.8 21

The device data shows that the inventive compound Cmp 84 providedsuperior performance vs. the comparative compound H001 in externalquantum efficiency (EQE).

It is understood that the various embodiments described herein are byway of example only, and are not intended to limit the scope of theinvention. For example, many of the materials and structures describedherein may be substituted with other materials and structures withoutdeviating from the spirit of the invention. The present invention asclaimed may therefore include variations from the particular examplesand preferred embodiments described herein, as will be apparent to oneof skill in the art. It is understood that various theories as to whythe invention works are not intended to be limiting.

We claim:
 1. A compound having a formula:

wherein R represents an adjacent di-substitution having the followingformula fused to ring A:

wherein the bonds with wave lines represent the bonds connected to twoadjacent carbon atoms from the ring A; wherein R^(A), and R^(C) eachindependently represents mono, di, tri, or tetra substitution, or nosubstitution; wherein R^(B) represents mono, or di substitution, or nosubstitution; wherein L¹ and L² each independently represents a directbond or an organic linker; wherein G¹ and G² are each independentlyselected from the group consisting of aryl, heteroaryl, substitutedvariants thereof, and combination thereof; wherein at least one of G¹and G² comprises a structure having the formula:

wherein X¹-X⁸ are each independently selected from the group consistingof C and N; wherein at least one of X¹-X⁸ is N; wherein the maximumnumber of N atoms in a ring can connect to each other is two; whereinR^(A), R^(B), R^(C), R^(D), and R^(E) are each independently selectedfrom the group consisting of hydrogen, deuterium, halogen, alkyl,cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy,amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl,heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile,sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; andwherein any two substituents may be joined or fused together to form aring.
 2. The compound of claim 1, wherein R^(A), R^(B), R^(C), R^(D),and R^(E) are each independently selected from the group consisting ofhydrogen, deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy,aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl,heteroaryl, nitrile, isonitrile, sulfanyl, and combinations thereof. 3.The compound of claim 1, wherein one of X¹-X⁸ is N, and the remainingX¹-X⁸ are C.
 4. The compound of claim 1, wherein two of X¹-X⁸ is N, andthe remaining X¹-X⁸ are C.
 5. The compound of claim 1, wherein L¹ and L²are independently selected from the group consisting of direct bond,aryl, substituted aryl, heteroaryl, and substituted heteroaryl.
 6. Thecompound of claim 1, wherein G¹ and G² each independently comprises astructure selected from the group consisting of phenyl, biphenyl,terphenyl, naphthalene, triphenylene, dibenzothiophene, dibenzofuran,carbazole, azacarbazole, imidazole, pyrazole, triazole, pyrimidine,quinazoline, quinoxaline and triazine.
 7. The compound of claim 1,wherein L¹ and L² are each independently selected from the groupconsisting of direct bond, aryl, and heteroaryl.
 8. The compound ofclaim 1, wherein the compound is selected from the group consisting of:

and wherein R′ has the same definition as R^(A), R^(B), R^(C), R^(D),and R^(E).
 9. The compound of claim 1, wherein the compound is selectedfrom the group consisting of:


10. An organic light emitting device (OLED) comprising: an anode; acathode; and an organic layer, disposed between the anode and thecathode, comprising a compound having a formula:

wherein R represents an adjacent di-substitution having the followingformula fused to ring A:

wherein the bonds with wave lines represent the bonds connected to twoadjacent carbon atoms from the ring A; wherein R^(A), and R^(C) eachindependently represents mono, di, tri, or tetra substitution, or nosubstitution; wherein R^(B) represents mono, or di substitution, or nosubstitution; wherein L¹ and L² each independently represents a directbond or an organic linker; wherein G¹ and G² are each independentlyselected from the group consisting of aryl, heteroaryl, substitutedvariants thereof, and combinations thereof; wherein at least one of G¹and G² comprises a structure having the formula:

wherein X¹-X⁸ are each independently selected from the group consistingof C and N; wherein at least one of X¹-X⁸ is N; wherein the maximumnumber of N atoms in a ring that can connect to each other is two;wherein R^(A), R^(B), R^(C), R^(D), and R^(E) are each independentlyselected from the group consisting of hydrogen, deuterium, halogen,alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy,aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl,aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile,isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinationsthereof; and wherein any two substituents may be joined or fusedtogether to form a ring.
 11. The OLED of claim 10, wherein the organiclayer is an emissive layer and the compound of Formula I is a host. 12.The OLED of claim 10, wherein the organic layer further comprises aphosphorescent emissive dopant; wherein the emissive dopant is atransition metal complex having at least one ligand or part of theligand if the ligand is more than bidentate, selected from the groupconsisting of:

wherein each X¹ to X¹³ are independently selected from the groupconsisting of carbon and nitrogen; wherein X is selected from the groupconsisting of BR′, NR′, PR′, O, S, Se, C═O, S═O, SO₂, CR′R″, SiR′R″, andGeR′R″; wherein R′ and R″ are optionally fused or joined to form a ring;wherein each R_(a), R_(b), R_(c), and R_(d) may represent from monosubstitution to the possible maximum number of substitution, or nosubstitution; wherein R′, R″, R_(a), R_(b), R_(c), and R_(d) are eachindependently selected from the group consisting of hydrogen, deuterium,halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl,alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl,alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile,isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinationsthereof; and wherein any two adjacent substituents of R_(a), R_(b),R_(c), and R_(d) are optionally fused or joined to form a ring or form amultidentate ligand.
 13. The OLED of claim 10, wherein the organic layeris a charge carrier blocking layer and the compound of claim 1 is acharge carrier blocking material in the organic layer.
 14. The OLED ofclaim 10, wherein the organic layer is a charge carrier transportinglayer and the compound of claim 1 is a charge carrier transportingmaterial in the organic layer.
 15. A consumer product comprising anorganic light-emitting device comprising: an anode; a cathode; and anorganic layer, disposed between the anode and the cathode, comprising acompound having a formula:

wherein R represents an adjacent di-substitution having the followingformula fused to ring A:

wherein the bonds with wave lines represent the bonds connected to twoadjacent carbon atoms from the ring A; wherein R^(A), and R^(C) eachindependently represents mono, di, tri, or tetra substitution, or nosubstitution; wherein R^(B) represents mono, or di substitution, or nosubstitution; wherein L¹ and L² each independently represents a directbond or an organic linker; wherein G¹ and G² are each independentlyselected from the group consisting of aryl, heteroaryl, substitutedvariants thereof, and combinations thereof; wherein at least one of G¹and G² comprises a structure having the formula:

wherein X¹-X⁸ are each independently selected from the group consistingof C and N; wherein at least one of X¹-X⁸ is N; wherein the maximumnumber of N atoms in a ring that can connect to each other is two;wherein R^(A), R^(B), R^(C), R^(D), and R^(E) are each independentlyselected from the group consisting of hydrogen, deuterium, halogen,alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy,aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl,aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile,isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinationsthereof; and wherein any two substituents may be joined or fusedtogether to form a ring.
 16. The consumer product of claim 15, whereinthe consumer product is selected from the group consisting of flat paneldisplays, curved displays, computer monitors, medical monitors,televisions, billboards, lights for interior or exterior illuminationand/or signaling, heads-up displays, fully or partially transparentdisplays, flexible displays, rollable displays, foldable displays,stretchable displays, laser printers, telephones, mobile phones,tablets, phablets, personal digital assistants (PDAs), wearable devices,laptop computers, digital cameras, camcorders, viewfinders,micro-displays, 3-D displays, virtual reality or augmented realitydisplays, vehicles, video walls comprising multiple displays tiledtogether, theater or stadium screen, and a sign.
 17. A formulationcomprising the compound of claim 1.